Violet vat dye and process of making same.



UNITED STATES PATENT OFFICE.

HERMANN KRAFT AND GADIENT ENGI, OF BASEL, SWITZERLAND, ASSIGNORS TO THEFIRM OF SOCIETY OF CHEMICAL INDUSTRY IN BASLE, OF BASEL, SWITZERLAND.

VIOLET VAT DYE AND PROCESS OF MAKING SAME.

To all whom it may concern:

Be it known that we, :HELM'ANN KRAFT, doctor of philosophy and chemist,a subject of the Emperor of AustriaHungary, and resident of Basel,Switzerland, and Graoirtn'r ENGI, doctor of philosophy and chemist, acitizen of the Swiss Republic, and resident of Basel, Switzerland, haveinvented new and useful Violet Vat Dyestuffs and a Process of litlakingSame, of which the following is a full, clear, and exact specification.

\Ve have found, that valuable violet vatdyestuffs can be obtained bycondensing the alphaarylids of 223(lill1OClil1yCl1O-I-tlliO- naphtheneor of its derivates, corresponding to the general formula \CO/ Y 1 withindoxyls and by subjecting the condensation product thus obtained to atreatment with a halogen or a halogenating agent.

The alphaarylids of 2:S-diketodihydro-lthionaphthene and of itsderivates employed as parent materials can be prepared easily by theaction of aromatic nitroso compounds on 3-oxy-l-thionaphthene and itssubstitution products.

Example. 23.7 parts of the anilid of the 2:3-diketodihydro-l-thionaphthene, melting at 147 O. (prepared bycondensing nitrosobenzene with 8-oxy-l-thionaphthene in an alcoholicsolution), 17.5 parts of acetindoxyl or 13.5 parts of indoXyl, 10 partsof sodium carbonate and 100 to 120 parts alcohol, are boiled together,on a water bath, for 3 hours. The liquid assumes a brownish-yel.

low coloration and the condensation product precipitates gradually. Thislatter is separated by filtration, washed with water and thus obtainedas small, dark violet, felted crystals of a copper reflex. In order totransform the product in a brominated dyestuilf, 14 parts of thiscondensation product are suspended in 100 to 140 parts of nitrobenzeneand to this suspension 27 parts of bromin are added and heated in thecourse of about 1. hours in an oil bath to 220230 C. After a furtherheating for 1 hour, the mass is cooled down and filtered and thedyestuff is washed with alcohol and dried. It constitutes a dark violetpowder of a copper luster, which dissolves in concentrated sulfuric acidwith a blue coloration turning to a greenish blue on heating. In hotalcohol it is ditli- Specification of Letters Patent.

Application filed April 22, 1908.

Patented Sept. 29, 1908.

Serial No. 428,690.

cultly soluble with a blue-violet coloration but it is more easilysoluble in hot nitrobenzene with a red-violet coloration. By itstreatment with alkaline reducing agents it yields a brownish yellow vatdyeing cotton splendid violet-blue tints becoming more reddish onsoaping. The dyeings are fast to washing, light and chlorin.

In an analogous manner'are prepared halogenated dyestuffs of similarproperties when the condensation products of indoXyl or its derivativeswith other arylids of 2: 3-diketodihydro-l-thionaphthene or of itssubstitution products are employed.

hat we claim is:

1. The herein described process for the manufacture of violetvat-dyestufis, which consists in condensing first an indoXyl-compoundwith an alpha-arylid of a 2: 3-diketodihydro-thionaphthene-compound andtreating then the so obtained condensation product with halogenatingagents.

2. The herein described process for the manufacture of violetvat-dyestuffs, which consists in treating the products obtainable by thecondensation of indoXyl-compounds with 2:3-diketodihydro-1-thionaphthenearylids, with halogenating agents.

3. The herein described process for the manufacture of a violetvat-dyestuif, which consists in first condensing indoxyl with the alphaanilid of 2: 3-diketodihydro-l-thionaphthene and treating then the soobtained product with bromin.

4. As new products, the halogenated vatdyestuffs obtainable by treatingthe condensation products of indoXyl-compounds and 2:3diketodihydrothionaphthene arylids with halogenating agents,constituting in dry state violet powders, dissolving in concentratedsulfuric acid with a blue to greenish blue coloration, soluble in hotnitrobenzene with a violet coloration and yielding, when treated withalkaline reducing agents, a brownish yellow vat dyeing cotton violet toviolet-blue tints fast to washing, light and chlorin.

5. As a new product, the halogenated vat dyestuif, obtainable bytreating the condensation product of in doxyl and 2:3-diketodihydro-l-thionaphthene-alphaanilid with bromin, constituting indry state a dark violet powder of copper luster, dissolving inconcentrated sulfuric acid with a pure blue color, difficultly solublein hot alcohol with a bluish-violet coloration, more easily soluble1908, in the presence of two subscribing Wit- 1n hot nltrohenzene wlth arecl-vlolet color-w nesses.

{ion and yielding, when treated With alka HEBMANN KPAFD ine recluclngagents, a brownish-yellow vat GALDIENT ENVY dyeing cotton vi01et-bluetints fast to Washing, light and chlorin. itnessesz In Witness whereofWe have hereunto G110. Girrom), signed our names this ninth clay ofApril ARNOLD ZU'BER.

